Phase 2: Classical Cryptography
Before we can understand why quantum computers threaten encryption, we need to understand how encryption actually works. This phase covers the cryptographic algorithms that secure every bank transfer, chat message, and HTTPS connection on the internet today.
What is Cryptography?
Ciphers, keys, plaintext, ciphertext — the vocabulary and core concepts of the science of secrets.
Start here →Symmetric Encryption (AES)
One key encrypts and decrypts. Learn how AES — the gold standard of symmetric ciphers — scrambles data into unreadable noise.
Explore AES →Asymmetric Encryption (RSA & ECC)
Public and private key pairs. How two strangers can securely exchange secrets over an insecure channel — and why this is mathematical magic.
Explore RSA & ECC →Hash Functions & Digital Signatures
One-way fingerprints for data. How SHA-256 and digital signatures prove authenticity without revealing secrets.
Explore hashing →TLS, SSL & Public Key Infrastructure
How HTTPS actually works. Certificate authorities, handshakes, and the trust chain that secures the web.
Explore TLS →